Valve element

ABSTRACT

Valve element ( 3, 6, 10 ), comprising a frame, at least one inlet and at least one outlet, a passage connecting the inlet and outlet, at least one burst disk ( 13, 35, 63 ) or equivalent, which, when unbroken, closes the passage from inlet to outlet, and a piston element ( 15, 36, 65 ) provided with a piercing element or the like for piercing the burst disk. The piston element ( 15, 36, 65 ) is provided with a passage ( 17, 39, 67 ) for a pressure medium, said passage extending axially through the piston element from one first side to one second side, which passage leading through the piston forms a part of the passage of the pressure medium after the burst disk ( 13, 35, 63 ) has been pierced.

BACKGROUND OF THE INVENTION

The present invention relates to a valve element as defined in thepreamble of claim 1, which comprises a frame, at least one inlet and atleast one outlet, a passage connecting the inlet and outlet and at leastone burst disk (rupture disk) or equivalent, which, when unbroken,closes the passage from inlet to outlet, and a piston element providedwith a piercing element or the like for piercing the burst disk.

A device corresponding to the subject of the invention is known fromspecification DE 2635076 A. One of the drawbacks of this solution isthat the piercing element is returned by the action of pressure back toits original position, so a piece of the burst disk that may have beendetached from it by the piercing action may partially block the passageand thus form an obstacle to the flow of pressure medium. In addition,the piercing element has to go completely through the burst disk inorder to produce a hole of the desired size in the disk. If the piercingmovement is for some reason incompletely executed, it will not produce ahole of the desired size.

The object of the present invention is to achieve a completely new typeof solution that makes it possible to avoid the drawbacks of prior-artdevices. The object of the invention is to create a reliable apparatusthat can be utilized especially in fire extinguishing applications.

The apparatus of the invention is characterized in that the pistonelement is provided with a passage for a pressure medium, said passageextending axially through the piston element from one first side to onesecond side, which passage leading through the piston forms a part ofthe passage of the pressure medium after the burst disk has beenpierced.

The apparatus of the invention is additionally characterized by what isstated in claims 2-7.

The solution of the invention has numerous significant advantages. Thepassage through the piston ensures that the piston will be effectivelypressed towards the burst disk after the disk has been pierced even incases where a higher pressure prevails on the opposite side of the burstdisk than on the side of the piston-piercer combination. The solution ofthe invention is leak-proof and reliable. By making the channel formedthrough the piston element a part of the passage for the pressuremedium, a passage having a constant diameter in all circumstances isachieved.

BRIEF DESCRIPTION OF THE FIGURES

In the following, the invention will be described in detail by the aidof an example with reference to the attached drawing, wherein

FIG. 1 presents an embodiment of the apparatus of the invention,

FIG. 2 presents a valve element according to the invention,

FIG. 3 presents another valve element according to the invention, and

FIG. 4 presents a third valve element according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a diagrammatic representation of a pressure system in which itis possible to utilize valve elements according to the invention. Thesystem comprises at least two parallel-connected pressure sources 4, 4′,which in the solution represented by the figure consist of four pressurecontainers 4, 4′ each. In addition, the system comprises at least onefirst pressure source 1 and means for opening a connecting passage fromthe first pressure source 1 to a pressure network 2, which communicateswith a first pressure source 4. The means for opening a connectingpassage comprise a first valve element 10, which is disposed between thefirst pressure source 1 and the pressure network 2. When the first valveelement 10 is opened, e.g. triggered by a control system 7 or manually,the pressure in the network 2 rises. This has the effect of openingsecond valve elements 3, which are disposed at least in the passage 5between the first pressure source 4 and the network 2. After thepressure in the network 2 has risen to a sufficient level, a third valveelement 6 will be opened at a pre-set pressure.

As the pressure In the network 2 is rising, a passage is opened from asecond pressure source 1′ to a fourth valve element 20. This keeps theconnection to the second branch 2′ of the pressure network closed untilthe pressure in the first pressure network 2 has fallen to apredetermined value. After this, the pressure in the second network 2′rises, with the result that valve elements 3 connected to at least onesecond pressure source 4′ open a passage 5′ into the second pressurenetwork 2′. The third valve element 6 is not opened until the pressurein the second pressure network 2′ has reached a predetermined value.

A more detailed view of the first valve element 10 is presented in FIG.2. The device comprises a frame 11 which has an inlet connectable to apressure source and an outlet connectable to an outgoing line. Providedbetween the inlet and the outlet is a burst disk 13 (rupture disk)which, when unbroken, closes the passage from the inlet to the outlet.The device also comprises means for piercing the burst disk 13. Thesemeans consist of a cylinder-piston combination in which the piston 15comprises a piercing element 14 formed on it, preferably on the side ofthe piston rod 16. The piston 15 has been arranged to be movable withina cylinder space 12 between a fist position, where the piercing element14 formed on the piston rod 16 is on the outlet side in relation to theburst disk 13, and a second position, where the piercing element extendsat least partially to the inlet side in relation to the burst disk 13.The piston is provided with at least one bore 17 extending through thepiston 15, preferably from the piercing element 14 to the opposite sideof the piston 15 so that, after the burst disk 13 has been pierced, apassage is formed from the inlet side to the outlet side. Formed at ornear the tip of the piercing element is at least one aperture 18extending into the bore 17, thus forming a part of the passage for thepressure medium after the burst disk 13 has been pierced. The cylinderspace is preferably provided with a sleeve part 110 which has an openingextending in the axial direction of the piston, the piston rod beingsubstantially sealedly fitted to move in the opening. The burst disk 13is sealedly fitted against the sleeve 110 and tightened by means of aninlet coupling 101. Furthermore, the device comprises actuating meansfor actuating the piston-piercer combination. The embodiment illustratedin FIG. 2 is provided with both a manual actuating element and anautomatic actuating element. The manual solution comprises a handwheel106, which, after removal of a cotter 107, can be turned to move itaxially towards the piston 15 according to the pitch of the thread 108.The axial movement is transmitted by a spacer 111 to the surface of thepiston 15 facing in the opposite direction relative to the piercingelement, thus causing the piercer to move towards the burst disk 13.Once the handwheel has been rotated sufficiently, the tip of the piercerwill pierce the burst disk, thus allowing the pressure medium to flowthrough the apertures 18 and the bore 17 to the outlet side. Thepressure medium is now admitted to the outlet 102 side of the piston 15,where the piston surface is larger than the cross-sectional area of thepiston rod, with the result that the piston 15 is moved by the action ofthe pressure towards the burst disk until it is stopped by the sleeve110. Thus, even a small hole in the burst disk 13 is sufficient to causethe piercer 14 to penetrate the burst disk through an area correspondingto the cross-section of the piercer.

A second actuating element is designed for remote control, whereby thevalve element is to be triggered by means of a control signal. Thecontrol signal is supplied via transmission means 8, such as conductors,typically from a control system. The control signal causes the piston ofthe actuating element to move towards piston 15. In a preferred case,the valve element comprises a connecting piece 109 placed between theactuating element 105 and the piston 15 and provided with bores 112 orsimilar relief holes to allow easier passage of the pressure medium fromthe channel 17 through the cylinder space 12 and channel 113 to theoutlet. The actuating element 105 is preferably an electrically operateddevice in which a control current detonates an explosive charge in theactuating element, thus causing the piston of the actuating element tobe vigorously thrust out. The actuating element can be connected to acontrol system, so the device can be used e.g. in connection with fireextinguishing equipment so that the impulse triggering the actuatingelement 105 is received from fire detectors and/or smoke detectors (notshown).

In the embodiment presented In the figure, the valve element 10 alsocomprises a second outlet 103 especially for venting purposes. To thissecond outlet it is possible to connect e.g. a valve element (not shown)which, when the valve element is in a state of readiness, vents anyleakage pressure but Is closed at high pressures.

There is also a second venting channel 104 leading out from the cylinderspace 12 to ensure that the piston will be able to move towards theburst disk without being obstructed by the pressure medium between thepiston and the burst disk, because the pressure medium can be let out ofthe space via the second venting channel 104.

Thus, the first valve element 10 is preferably a triggering valve usedto trigger a pressure medium system.

After the triggering of the first valve element 10, pressure is admittedvia the outlet into the first line 2. The pressure in the line thereforerises, and the second valve elements 3 open a passage from the pressuresource 4 into the first line 2. The second valve elements 3 comprise aframe 31, a first connection 32 to line 5, a second connection 33 to thepressure source, a cylinder chamber 34 and a burst disk 35, which is soarranged that, while unbroken, it closes the passage between the firstand the second connections. The device also comprises means for piercingthe burst disk 35. These means consist of a cylinder-piston combinationin which the piston 36 comprises a piercing element 37 formed on it,preferably on the side of the piston rod 38. The piston 36 has beenarranged to be movable in the cylinder space 34 between a fist position,where the piercing element 37 formed on the piston rod 38 is on the sideof the first connection 32 in relation to the burst disk 35, and asecond position, where the piercing element 37 extends at leastpartially to the side of the second connection 33 in relation to theburst disk 35. The piston is provided with at least one bore 39extending through the piston, preferably from the piercing element 37 tothe opposite side of the piston so that, after the burst disk 35 hasbeen pierced, a passage is formed from the side of the second connectionto the side of the first connection. Formed at or near the tip of thepiercing element is at least one aperture 40 extending into the bore 39,thus forming a part of the passage for the pressure medium after theburst disk 35 has been pierced, or at least facilitating the admissionof the pressure medium into the bore 39. As the pressure in the line isincreasing, the piston element moves towards the burst disk and the tipof the piercing element penetrates the burst disk. The pressure mediumfrom the pressure source 4 can propagate via the second connection andthrough the passage formed by the hole made in the burst disk and thebore in the piston element out via the first connection and line 5 intoline 2. The pressure medium is now admitted to the side of the piston 36facing towards the first connection, where the piston surface 41 islarger than the cross-sectional area of the piston rod, with the resultthat the piston 36 is moved by the action of the pressure towards theburst disk 35 until it is stopped by the sleeve 42. Thus, even a smallhole in the burst disk 35 is sufficient to cause the piercing element 37to penetrate the burst disk through an area corresponding to thecross-section of the piercer. The burst disk and the piercing elementand the forces applied to them are so adapted in relation to each otherthat the burst disk will be at least partially pierced by the piercingelement at a desired pressure. Thus, the second valve element 3 ispreferably a closing valve of the second pressure source, being openedby a pressure impulse received from the first pressure source.

To raise the pressure in line 2 to a sufficient level, it can beprovided with a third valve element 6. This valve element is alsoprovided with a burst disk designed to be pierced, preferably by meansof a piston-piercer combination, after the pressure on the inlet sidehas risen to a sufficient level. The device comprises a frame 61 and acylinder space 62 with an inlet 68 from line 2 and an outlet 69.Disposed between the inlet and the outlet is at least one burst disk 63which, when unbroken, closes the passage between the inlet and theoutlet. Fitted in the cylinder space is a piston element 65 on the inletside of the burst disk, the piston element being provided with apiercing element 64 preferably formed on the piston rod 66. In theembodiment illustrated in FIG. 4, the burst disk 63 is sealedly fittedbetween a coupling part 70 designed to connect the valve element to theline 2 and a sleeve 71 provided in the frame. When the pressure on theinlet side reaches a predetermined value, the piercing element with atleast one aperture 78 will pierce the burst disk, thus opening a passagefrom the inlet side to the outlet side, preferably through a bore 67formed in the piston.

In all the above-described embodiments, the piston rod 16, 38, 66 of thepiston element is sealedly fitted against the wall of the cylinderspace, so that the pressure medium can typically only flow via thepassage provided through the piston.

The burst disk is preferably designed to withstand high pressures andpressure differences. The active pressures are typically over 30 bar,preferably over 70 bar. The pressures may even be as high as 300 bar.The burst disk preferably comprises a thinner part in the area to whichthe action of the piercing element is applied In the triggeringsituation.

Valve elements according to the invention can be applied especially inconnection with fire extinguishing systems, especially in connectionwith a fire extinguishing apparatus using high-pressure water mist. Thepressure medium may consist of gas, liquid or a mixture of gas andliquid.

It is obvious to the person skilled In the art that the invention is notlimited to the embodiments described above, but that it may be variedwithin the scope of the claims presented below.

1. Valve element (3, 6, 10), comprising a frame, at least one inlet andat least one outlet, a passage connecting the inlet and outlet, at leastone burst disk (rupture disk) (13, 35, 63) or equivalent, which, whenunbroken, closes the passage from inlet to outlet, and a piston element(15, 36, 65) provided with a piercing element or the like for piercingthe burst disk, characterized in that the piston rod (16, 38, 66) of thepiston element is sealedly fitted against the wall of the cylinderspace, that the piston element (15, 36, 65) is provided with a passage(17,39, 67) for a pressure medium, said passage extending axiallythrough the piston element from one first side to one second side, whichpassage leading through the piston forms a part of the passage of thepressure medium after the burst disk (13, 35, 63) has been pierced, andthat the cross-sectional area of the piston rod is smaller than thepiston surface.
 2. Valve element according to claim 1, characterized inthat the piercing element (14, 37, 64) is provided with at least oneaperture (18, 40, 68) extending from the outer surface of the pistonelement to the passage (17, 39, 67) leading through the piston element.3. Valve element according to claim 1, characterized in that the devicecomprises means (105, 106) for actuating the piston element.
 4. Valveelement according to claim 1, characterized in that the valve elementadditionally comprises a manual (106) and/or an automatic (105) meansfor actuating the piston element.
 5. Valve element according to claim 1,characterized in that the valve element (10) is a triggering valve forthe triggering of a pressure medium system.
 6. Valve element accordingto claim 1, characterized in that the valve element (3) is the closingvalve of a second pressure source and that it is opened by a pressureimpulse received from a first pressure source.